RARE EXAMPLE OF A MONOMERIC ARYLLITHIUM COMPLEX - X-RAY CRYSTAL-STRUCTURE OF (2,4,6-TRIPHENYLPHENYL)LITHIUM-BIS(DIETHYL ETHER)

Lithiation of 1-bromo-2,4,6-triphenylbenzene with n-butyllithium in diethyl ether gives (2,4,6-triphenyl-phenyl)lithium-bis(diethyl ether), whose X-ray crystal structure has been determined. This compound is a rare example of a monomeric organolithium reagent: the lithium atom adopts a planar three-coordinate geometry defined by the ipso carbon of the 2,4,6-triphenylphenyl group and two oxygen atoms of the diethyl ether solvate molecules; Li-C = 2.08 (2) angstrom, Li-O = 1.93 (1) angstrom, = 124.0 (4)-degrees, O-Li-O = 112.0 (8)-degrees. Crystal data for LiC32H37O2 at 26-degrees-C: monoclinic, space group I2/a, with a = 11.732 (7) angstrom, b = 20.538 (13) angstrom, c = 11.723 (9) angstrom, beta = 95.06 (6)-degrees, V = 2814 (3) angstrom3, Z = 4, R(F) = 0.067, R(wF) = 0.064 for 153 variables and 783 observed reflections.